Other air assets taking part in this first day : 6 French Boeing C135 (Bretagne squadron) and 1 E-3F from Istres and Avor Air bases.

EA-18G Growler with their 2 ALQ-99 jaming pods ready to take off

American EA-18G Growler have also been seen on an Italian Air base and will take part in the SEAD operations.

At 05h45PM, the French MoD revealed that one of those fighters shot at a military Libyan vehicule.
Edit 1 : Qatar TV, Al Jazzeera is reporting that at least 4 Libyan tanks would have been detroyed by French fighters.
Edit 2 : It is now confirmed that a Rafale B from the Gascogne squadron has attaked a Libyan tank column with its AASM bombs detroying 4 of them.

French fighters engaged in the first stage of the operations over Libya

Source: Press conference of the French defense Ministry.BBC News
Thanks to Tmor for additional info ;)